I think Kinoma does a great job with content and organization of their media. If you combined Kinoma's content and intuitiveness with Pockettunes ability to play in the background and management of playlists, you'd have one heck of an app.

Pockettunes also seems to buffer their content differently, though I wouldn't venture to say how. I just know that I can travel my entire commute without missing a note with PTunes, but Kinoma seems to buffer a bit more. And I'm in an EVDO area.

I do think Kinoma has a winner, given their rich media content and organization.